zebra: Make connected routes their own entry on the meta_q

During quick ifdown / ifup events from the linux kernel there
exists a situation where a prefix that has both a kernel route
and a static route can queued up on the meta-q.  If the static
route happens to point at a connected route for nexthop resolution
and we receive a series of quick up/down events *after* the
static route and kernel route are queued up for rib reprocessing.
Since the static route and kernel route are queued on meta-q 1
and the connected route is also on meta-q 1 there exists a situation
where the connected route will be resolved after the static route
fails to resolve, leaving the static route in a unresolved state.

Add a new queue level and put connected routes on their own level,
since they are the fundamental building blocks of pretty much
all the other routes.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>

2 files changed, 36 insertions, 34 deletions

diff --git a/zebra/rib.h b/zebra/rib.h
index be680a112f..38f8029791 100644
--- a/zebra/rib.h
+++ b/zebra/rib.h
@@ -165,13 +165,15 @@ struct route_entry {
 
 /* meta-queue structure:
  * sub-queue 0: nexthop group objects
- * sub-queue 1: connected, kernel
- * sub-queue 2: static
- * sub-queue 3: RIP, RIPng, OSPF, OSPF6, IS-IS, EIGRP, NHRP
- * sub-queue 4: iBGP, eBGP
- * sub-queue 5: any other origin (if any)
+ * sub-queue 1: connected
+ * sub-queue 2: kernel
+ * sub-queue 3: static
+ * sub-queue 4: RIP, RIPng, OSPF, OSPF6, IS-IS, EIGRP, NHRP
+ * sub-queue 5: iBGP, eBGP
+ * sub-queue 6: any other origin (if any) typically those that
+ *              don't generate routes
  */
-#define MQ_SIZE 6
+#define MQ_SIZE 7
 struct meta_queue {
 	struct list *subq[MQ_SIZE];
 	uint32_t size; /* sum of lengths of all subqueues */
diff --git a/zebra/zebra_rib.c b/zebra/zebra_rib.c
index 5d4eeaafd6..f56f585e9a 100644
--- a/zebra/zebra_rib.c
+++ b/zebra/zebra_rib.c
@@ -79,35 +79,35 @@ static const struct {
 	uint8_t meta_q_map;
 } route_info[ZEBRA_ROUTE_MAX] = {
 	[ZEBRA_ROUTE_NHG] = {ZEBRA_ROUTE_NHG, 255 /* Uneeded for nhg's */, 0},
-	[ZEBRA_ROUTE_SYSTEM] = {ZEBRA_ROUTE_SYSTEM, 0, 5},
-	[ZEBRA_ROUTE_KERNEL] = {ZEBRA_ROUTE_KERNEL, 0, 1},
+	[ZEBRA_ROUTE_SYSTEM] = {ZEBRA_ROUTE_SYSTEM, 0, 6},
+	[ZEBRA_ROUTE_KERNEL] = {ZEBRA_ROUTE_KERNEL, 0, 2},
 	[ZEBRA_ROUTE_CONNECT] = {ZEBRA_ROUTE_CONNECT, 0, 1},
-	[ZEBRA_ROUTE_STATIC] = {ZEBRA_ROUTE_STATIC, 1, 2},
-	[ZEBRA_ROUTE_RIP] = {ZEBRA_ROUTE_RIP, 120, 3},
-	[ZEBRA_ROUTE_RIPNG] = {ZEBRA_ROUTE_RIPNG, 120, 3},
-	[ZEBRA_ROUTE_OSPF] = {ZEBRA_ROUTE_OSPF, 110, 3},
-	[ZEBRA_ROUTE_OSPF6] = {ZEBRA_ROUTE_OSPF6, 110, 3},
-	[ZEBRA_ROUTE_ISIS] = {ZEBRA_ROUTE_ISIS, 115, 3},
-	[ZEBRA_ROUTE_BGP] = {ZEBRA_ROUTE_BGP, 20 /* IBGP is 200. */, 4},
-	[ZEBRA_ROUTE_PIM] = {ZEBRA_ROUTE_PIM, 255, 5},
-	[ZEBRA_ROUTE_EIGRP] = {ZEBRA_ROUTE_EIGRP, 90, 3},
-	[ZEBRA_ROUTE_NHRP] = {ZEBRA_ROUTE_NHRP, 10, 3},
-	[ZEBRA_ROUTE_HSLS] = {ZEBRA_ROUTE_HSLS, 255, 5},
-	[ZEBRA_ROUTE_OLSR] = {ZEBRA_ROUTE_OLSR, 255, 5},
-	[ZEBRA_ROUTE_TABLE] = {ZEBRA_ROUTE_TABLE, 150, 2},
-	[ZEBRA_ROUTE_LDP] = {ZEBRA_ROUTE_LDP, 150, 5},
-	[ZEBRA_ROUTE_VNC] = {ZEBRA_ROUTE_VNC, 20, 4},
-	[ZEBRA_ROUTE_VNC_DIRECT] = {ZEBRA_ROUTE_VNC_DIRECT, 20, 4},
-	[ZEBRA_ROUTE_VNC_DIRECT_RH] = {ZEBRA_ROUTE_VNC_DIRECT_RH, 20, 4},
-	[ZEBRA_ROUTE_BGP_DIRECT] = {ZEBRA_ROUTE_BGP_DIRECT, 20, 4},
-	[ZEBRA_ROUTE_BGP_DIRECT_EXT] = {ZEBRA_ROUTE_BGP_DIRECT_EXT, 20, 4},
-	[ZEBRA_ROUTE_BABEL] = {ZEBRA_ROUTE_BABEL, 100, 3},
-	[ZEBRA_ROUTE_SHARP] = {ZEBRA_ROUTE_SHARP, 150, 5},
-	[ZEBRA_ROUTE_PBR] = {ZEBRA_ROUTE_PBR, 200, 5},
-	[ZEBRA_ROUTE_BFD] = {ZEBRA_ROUTE_BFD, 255, 5},
-	[ZEBRA_ROUTE_OPENFABRIC] = {ZEBRA_ROUTE_OPENFABRIC, 115, 3},
-	[ZEBRA_ROUTE_VRRP] = {ZEBRA_ROUTE_VRRP, 255, 5},
-	[ZEBRA_ROUTE_SRTE] = {ZEBRA_ROUTE_SRTE, 255, 5},
+	[ZEBRA_ROUTE_STATIC] = {ZEBRA_ROUTE_STATIC, 1, 3},
+	[ZEBRA_ROUTE_RIP] = {ZEBRA_ROUTE_RIP, 120, 4},
+	[ZEBRA_ROUTE_RIPNG] = {ZEBRA_ROUTE_RIPNG, 120, 4},
+	[ZEBRA_ROUTE_OSPF] = {ZEBRA_ROUTE_OSPF, 110, 4},
+	[ZEBRA_ROUTE_OSPF6] = {ZEBRA_ROUTE_OSPF6, 110, 4},
+	[ZEBRA_ROUTE_ISIS] = {ZEBRA_ROUTE_ISIS, 115, 4},
+	[ZEBRA_ROUTE_BGP] = {ZEBRA_ROUTE_BGP, 20 /* IBGP is 200. */, 5},
+	[ZEBRA_ROUTE_PIM] = {ZEBRA_ROUTE_PIM, 255, 6},
+	[ZEBRA_ROUTE_EIGRP] = {ZEBRA_ROUTE_EIGRP, 90, 4},
+	[ZEBRA_ROUTE_NHRP] = {ZEBRA_ROUTE_NHRP, 10, 4},
+	[ZEBRA_ROUTE_HSLS] = {ZEBRA_ROUTE_HSLS, 255, 6},
+	[ZEBRA_ROUTE_OLSR] = {ZEBRA_ROUTE_OLSR, 255, 6},
+	[ZEBRA_ROUTE_TABLE] = {ZEBRA_ROUTE_TABLE, 150, 3},
+	[ZEBRA_ROUTE_LDP] = {ZEBRA_ROUTE_LDP, 150, 6},
+	[ZEBRA_ROUTE_VNC] = {ZEBRA_ROUTE_VNC, 20, 5},
+	[ZEBRA_ROUTE_VNC_DIRECT] = {ZEBRA_ROUTE_VNC_DIRECT, 20, 5},
+	[ZEBRA_ROUTE_VNC_DIRECT_RH] = {ZEBRA_ROUTE_VNC_DIRECT_RH, 20, 5},
+	[ZEBRA_ROUTE_BGP_DIRECT] = {ZEBRA_ROUTE_BGP_DIRECT, 20, 5},
+	[ZEBRA_ROUTE_BGP_DIRECT_EXT] = {ZEBRA_ROUTE_BGP_DIRECT_EXT, 20, 5},
+	[ZEBRA_ROUTE_BABEL] = {ZEBRA_ROUTE_BABEL, 100, 4},
+	[ZEBRA_ROUTE_SHARP] = {ZEBRA_ROUTE_SHARP, 150, 6},
+	[ZEBRA_ROUTE_PBR] = {ZEBRA_ROUTE_PBR, 200, 6},
+	[ZEBRA_ROUTE_BFD] = {ZEBRA_ROUTE_BFD, 255, 6},
+	[ZEBRA_ROUTE_OPENFABRIC] = {ZEBRA_ROUTE_OPENFABRIC, 115, 4},
+	[ZEBRA_ROUTE_VRRP] = {ZEBRA_ROUTE_VRRP, 255, 6},
+	[ZEBRA_ROUTE_SRTE] = {ZEBRA_ROUTE_SRTE, 255, 6},
 	/* Any new route type added to zebra, should be mirrored here */
 
 	/* no entry/default: 150 */